We have a cycling studio/ bike gym. We offer classes and you need a membership to reserve a class. This is very similar to a gym membership. I just need to make sure how the payments will work. According to the guideline 3.1.3(e) Goods and Services Outside of the App I think we can offer payments with a traditional credit card entry. Is this so? Because in the forum I found answers stating you need to use in-app-purchase. I really need to make sure before beginning the app development. Thank you.